A plug-in connector part of this kind comprises a housing that has a plug-in portion for plug-in connection to the mating plug-in connector part, and at least one contact element, arranged on the plug-in portion and having a shaft portion, for electrically contacting an associated mating contact element of the mating plug-in connector part.
A plug-in connector part of this kind can be used, for example, as a charging plug or as a charging socket for charging an electrically powered vehicle (also referred to as an electric vehicle). A charging socket of this kind is arranged, for example, on a vehicle and can be connected in a plug-in manner to an associated mating plug-in connector part in the form of a charging plug on a cable that is connected to a charging station, in order to thus establish an electrical connection between the charging station and the vehicle.
In principle, charging currents can be transmitted as direct currents or alternating currents, charging currents in the form of direct current in particular having a high amperage, for example greater than 200 A or even greater than 300 A or even 350 A, it being possible for said charging currents to cause the cable, as well as a plug-in connector part connected to the cable, to heat up.
A charging cable known from DE 10 2010 007 975 B4 has a cooling line which comprises a supply line and a return line for a coolant, therefore allowing a coolant to flow in and out of the charging cable. The cooling line in DE 10 2010 007 975 B4 is used to dissipate heat produced due to energy loss from an energy store of a vehicle, but also to additionally cool the cable itself.
In a charging system for charging an electric vehicle, heat is produced not only in the cable by means of which a charging plug is connected to a charging station, for example, but also in the charging plug and in a charging socket into which the charging plug is plugged. In this case, heat is produced in particular in contact elements, for example of the charging socket, by means of which elements electrical contact with associated mating contact elements is produced, for example by a charging socket, when the charging plug is plugged into the charging socket.
Contact elements of this kind, which are made of an electrically conductive metal material, for example a copper material, are heated up when a charging current flows via the contact elements, which, in principle, are dimensioned on the basis of the charging current to be transmitted and such that the contact elements have a sufficient current-carrying capacity and the heating of the contact elements is limited. In this case, a contact element is dimensioned so as to be larger the higher the charging current to be transmitted is.
However, limits are set on scaling the size of the contact element against increasing charging current, not only on account of the associated installation space requirements, the weight and the costs, but additionally there are normative standards for the dimensioning of the contact elements that preclude scaling. There is therefore a requirement to transmit a high charging current by means of a relatively small contact element.
In a charging system known from WO 2015/119791 A1 for charging an electric vehicle, coolant lines are guided inside a charging cable, by means of which lines heat can also be dissipated from the region of a plug-in connector part connected to the charging cable.
In a charging system known from U.S. Pat. No. 5,909,099, charging currents are transmitted, using a transformer, via a core arranged in a plug-in connector part. A heating line for dissipating heat can be extended in the core.